LOANS AND ALLOWANCE FOR LOAN LOSSES (PCI Loan Portfolios by Segment and Delinquency Status) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	$ 12,048,627	$ 9,537,156
Total Loans	12,220,514	9,716,207
Construction and Land Development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	1,246,412	1,177,204
Total Loans	1,267,712	1,194,821
Commercial Real Estate - Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	1,925,839	1,294,975
Total Loans	1,966,776	1,337,345
Commercial Real Estate - Non-Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	3,085,589	2,447,907
Total Loans	3,104,823	2,467,410
Multifamily Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	600,805	547,997
Total Loans	602,115	548,231
Commercial & Industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	2,022,993	1,309,581
Total Loans	2,032,799	1,317,135
Residential 1-4 Family - Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	781,757	687,957
Total Loans	801,703	713,750
Residential 1-4 Family - Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	813,950	556,907
Total Loans	850,063	600,578
Auto
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	308,861	297,442
Total Loans	311,858	301,943
HELOC
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	647,348	600,055
Total Loans	660,621	613,383
Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	377,533	376,057
Total Loans	383,653	379,694
Other Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	237,540	241,074
Total Loans	238,391	241,917
Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	85,583	71,213
Total Loans	101,301	90,221
Purchased Impaired | 30 To 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	3,553	4,264
Purchased Impaired | Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	12,165	14,744
Purchased Impaired | Construction and Land Development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	10,720	7,122
Total Loans	12,181	8,654
Purchased Impaired | Construction and Land Development | 30 To 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	165	108
Purchased Impaired | Construction and Land Development | Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,296	1,424
Purchased Impaired | Commercial Real Estate - Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	27,909	20,705
Total Loans	32,628	25,644
Purchased Impaired | Commercial Real Estate - Owner Occupied | 30 To 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	745	658
Purchased Impaired | Commercial Real Estate - Owner Occupied | Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	3,974	4,281
Purchased Impaired | Commercial Real Estate - Non-Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	14,640	15,464
Total Loans	15,755	17,335
Purchased Impaired | Commercial Real Estate - Non-Owner Occupied | 30 To 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	116	61
Purchased Impaired | Commercial Real Estate - Non-Owner Occupied | Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	999	1,810
Purchased Impaired | Multifamily Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	92	88
Total Loans	92	88
Purchased Impaired | Multifamily Real Estate | 30 To 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	0
Purchased Impaired | Multifamily Real Estate | Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	0
Purchased Impaired | Commercial & Industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	2,604	1,017
Total Loans	3,930	2,156
Purchased Impaired | Commercial & Industrial | 30 To 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	245	47
Purchased Impaired | Commercial & Industrial | Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,081	1,092
Purchased Impaired | Residential 1-4 Family - Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	11,423	9,312
Total Loans	12,675	13,707
Purchased Impaired | Residential 1-4 Family - Commercial | 30 To 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	582	931
Purchased Impaired | Residential 1-4 Family - Commercial | Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	670	3,464
Purchased Impaired | Residential 1-4 Family - Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	12,619	12,455
Total Loans	17,821	16,766
Purchased Impaired | Residential 1-4 Family - Mortgage | 30 To 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,423	1,899
Purchased Impaired | Residential 1-4 Family - Mortgage | Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	3,779	2,412
Purchased Impaired | Auto
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	7	7
Total Loans	7	7
Purchased Impaired | Auto | 30 To 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	0
Purchased Impaired | Auto | Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	0
Purchased Impaired | HELOC
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	4,231	4,365
Total Loans	4,869	5,115
Purchased Impaired | HELOC | 30 To 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	277	498
Purchased Impaired | HELOC | Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	361	252
Purchased Impaired | Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	684	18
Total Loans	689	32
Purchased Impaired | Consumer | 30 To 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	5
Purchased Impaired | Consumer | Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	5	9
Purchased Impaired | Other Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	654	660
Total Loans	654	717
Purchased Impaired | Other Commercial | 30 To 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	57
Purchased Impaired | Other Commercial | Greater than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	$ 0	$ 0